[Mathematical models in epidemiology: Study on viral hepatitis in Italy (author's transl)].

In this paper a mathematical approach to the epidemics is proposed. The method is based upon a model able to describe any time-depending phenomena using the following elements: "class", "transition" and "related probability". The solution of the differential equations describing the model are obtained: first, by numerical techniques; second, by a Montecarlo simulation method. Deterministic and stochastic solutions which have been obtained, by applying the model to the study of viral hepatitis in Italy during 1960--1970, have been compared each other, to improve the model itself.